I decided to drive the Jeep around town today to run some errands and hit the freeway since I have not been at freeway speeds yet since the stretch. It drove good on the freeway but there was a somewhat rhythmic high frequency vibe around 70 mph. It was there before the stretch but didn't seem as prevalent. It felt like a driveshaft vibe..... and I believe it is. I've got some considerable play in the splined portion of my front driveshaft. I think when I pulled the t-case and pulled the front drive shaft apart on accident I failed to orientate it the same way during reassembly. I'm not blaming the wear on that, (I blame the lack of a boot, grease, or any maintenance over the years on that particular part) but I think it may be why the condition is more prevalent than before. I'm actually not sure how much play in those splines is acceptable, I assume NONE, like my new rear shaft is. Just to clarify, by play I mean you can grab the shaft where the two pieces connect and feel movement where the splines are not firmly engaging each other. Can anyone go out and grab their DRIVEshaft and see if it's got any play in it?????

It figures I spend all of, and then some, of the Jeep money I've saved up the last couple months and end up needing a general maintenance repair! Haha. Oh well.

Take the driveshaft out, drive it and see if the problem disappears. Some play on the splines is ok, As long as there isn't a lot of driveshaft run out you should be ok. Does the front shaft have a dead spline so you cannot misalign it?

Take the driveshaft out, drive it and see if the problem disappears. Some play on the splines is ok, As long as there isn't a lot of driveshaft run out you should be ok. Does the front shaft have a dead spline so you cannot misalign it?

I don't think it has a dead spline, I remember it coming apart with me having no idea how it was before, so I just stuck it back together, haha. If it does have a dead spline for alignment I just got lucky and hit it just right. It's a pretty considerable amount of play though, not just a little click of movement.

It's not a huge deal, I rarely go that fast in it, I just did today as a test. This is something that I want to fix, but not with much urgency.

I don't think it has a dead spline, I remember it coming apart with me having no idea how it was before, so I just stuck it back together, haha. If it does have a dead spline for alignment I just got lucky and hit it just right. It's a pretty considerable amount of play though, not just a little click of movement.

It's not a huge deal, I rarely go that fast in it, I just did today as a test. This is something that I want to fix, but not with much urgency.

In case it doesn't the Yokes got to align, just like the rear driveshaft.
If it is out of time it will cause vibration and or a rumble.

I don't think it has a dead spline, I remember it coming apart with me having no idea how it was before, so I just stuck it back together, haha. If it does have a dead spline for alignment I just got lucky and hit it just right. It's a pretty considerable amount of play though, not just a little click of movement.

It's not a huge deal, I rarely go that fast in it, I just did today as a test. This is something that I want to fix, but not with much urgency.

It would bother me! Let's see, what's the speed limit on I5? But, then again, I don't have a trailer to drag my "dedicated trail rig" to places. Oops! Did I say that outloud? I need to use my "inside voice"!

It would bother me! Let's see, what's the speed limit on I5? But, then again, I don't have a trailer to drag my "dedicated trail rig" to places. Oops! Did I say that outloud? I need to use my "inside voice"!

It's really minimal Bob, but barely there and honestly if I wasn't purposely shaking it down, listening and feeling every little thing I probably wouldn't even be looking into it. Don't worry.... I'm thinking of doing something a little crazy in the next couple weeks.... involving me driving my rig somewhere far, wheeling it for a long time, and then driving home. Alone. We'll see how it works out though....